A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section and increase overall propulsive efficiency of the engine.
A fan exit guide vane is generally provided aft of the fan and forward of structural components within bypass passages such as an upper bifurcation that include structures for attaching the engine to the airframe. The combination of the fan exit guide vane and structural components aft of the fan can create an unsteady pressure distortion at the fan blade. Relationships between the rotating fan and components within the bypass duct can contribute to the propagation of noise from the nacelle. The unsteady pressure distortion patterns at the fan blade can generate undesirable levels of noise.
Accordingly, it is desirable to design and develop a fan exit guide vane that reduces unsteady distortion patterns and prevent propagation of noise from the nacelle.